My Wife Is Suffering From Alternating Pain In Her Knee

My wife is suffering from alternating pain in her knee area and swelling in her upper legs. She is in menopause and hasn't had a period for about 6 to 8 months. She has had some mild degree of discomfort for several years, but just lately it seems to be getting worse. she is not retaining water and there is no heat or redness and it is tender to touch her knees when it flares up.